• Journal of the Korean Society of Marine Environment & Safety
• /
• v.21 no.5
• /
• pp.577-582
• /
• 2015

This paper is the fundamental study for the application of cold storage system to the transportation equipment by sea and land. This numerical study presents the solid-liquid phase change phenomenon of calcium chloride solution of 30wt %. The governing equations are 1-dimensional unsteady state heat transfer equations of $1^{st}$ order partial differential equations. This type of latent heat storage material is often usable in fishery vessel for controlling the temperature of container with constant condition. The governing equation was discretized with finite difference method and the program was composed with Mathcad program. The main parameters of this solution were the initial temperature of heat storage material, ambient temperature of cold air and the velocity of cold air. The data of boundary layer thickness becomes thin with the increasing of cold air flowing velocity and also the heat storage completion time become shorten.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
• /
• v.20 no.2
• /
• pp.95-97
• /
• 1991

• Journal of Korean Medical classics
• /
• v.36 no.1
• /
• pp.45-78
• /
• 2023

Objectives : Based on the Zangfuyaoshibuzheng of Zhang Shanlei, this paper examines the tip/root division of the Zangfu, features of medicinal application according to deficiency/excess or cold/heat, and erroneous cases in the Zangfuxushibiaobenyongyaoshi of Zhang Jiegu. Methods : Categorization according to tip/root, cold/heat, deficiency/excess and respective medicinal applications in the Zangfuxushibiaobenyongyaoshi were organized, followed by thorough analysis based on the annotations in the Zangfuyaoshibuzheng. Results : First, in the treatment principle of the Zangfu diseases, each of their physiological function and pathological mechanism were analyzed so that the disease patterns are understood accurately and treated accordingly. Second, in categorizing treatment methods, terminology application was modified in overlapping or ambiguous cases so that they could be better distinguished. Third, medicinal categories that were designated to treat each Zangfu disease were explained well based on unique features. In cases where medicinals were falsely included, they were identified and corrected based on sound reasoning. Conclusions : The pattern diagnosis in the Zangfuyaoshibuzheng is clear, and medicinal application analysis is intelligible. As it thoroughly corrects and revises errors in Zhang Jiegu's theories, it could provide valuable assistance in selecting each medicinals when treating disease patterns of the Five Zang.

• Nuclear Engineering and Technology
• /
• v.44 no.5
• /
• pp.523-534
• /
• 2012

The objective of this study was to experimentally investigate the effect of heat curing methods on the temperature history and strength development of slab concrete exposed to $-10^{\circ}C$. The goal was to determine proper heat curing methods for the protection of nuclear power plant structures against early-age frost damage under adverse (cold) conditions. Two types of methods were studied: heat insulation alone and in combination with a heating cable. For heat curing with heat insulation alone, either sawdust or a double layer bubble sheet (2-BS) was applied. For curing with a combination of heat insulation and a heating cable, an embedded heating cable was used with either a sawdust cover, a 2-BS cover, or a quadruple layer bubble sheet (4-BS) cover. Seven different slab specimens with dimensions of $1200{\times}600{\times}200$ mm and a design strength of 27 MPa were fabricated and cured at $-10^{\circ}C$ for 7 d. The application of sawdust and 2-BS allowed the concrete temperature to fall below $0^{\circ}C$ within 40 h after exposure to $-10^{\circ}C$, and then, the temperature dropped to $-10^{\circ}C$ and remained there for 7 d owing to insufficient thermal resistance. However, the combination of a heating cable plus sawdust or 2-BS maintained the concrete temperature around $5^{\circ}C$ for 7 d. Moreover, the combination of the heating cable and 4-BS maintained the concrete temperature around $10^{\circ}C$ for 7 d. This was due to the continuous heat supply from the heating cable and the prevention of heat loss by the 4-BS. For maturity development, which is an index of early-age frost damage, the application of heat insulation materials alone did not allow the concrete to meet the minimum maturity required to protect against early-age frost damage after 7 d, owing to poor thermal resistance. However, the combination of the heating cable and the heat insulating materials allowed the concrete to attain the minimum maturity level after just 3 d. In the case of strength development, the heat insulation materials alone were insufficient to achieve the minimum 7-d strength required to prevent early-age frost damage. However, the combination of a heating cable and heat insulating materials met both the minimum 7-d strength and the 28-d design strength owing to the heat supply and thermal resistance. Therefore, it is believed that by combining a heating cable and 4-BS, concrete exposed to $-10^{\circ}C$ can be effectively protected from early-age frost damage and can attain the required 28-d compressive strength.

• Journal of Korean Medical classics
• /
• v.29 no.1
• /
• pp.139-172
• /
• 2016

Objectives : The purpose of research thesis is an advanced interpretation of the Name of Constitutional Disease of Dong-uisusebowon(東醫壽世保元) 1901 edition(辛丑本) evaluated to interpretation incompleted, and application of clinical diagnosis by rivised interpretation. Methods : A study on translation of sasangin(四象人)'s constitutional disease is researched the methods of documentary research on Dong-uisusebowon(東醫壽世保元) 1901 edition(辛丑本) and 1894 edition(甲午本). Results : Result of analysis of 4 meaning unit is as follows. Viscera or entrails means root or terminus of organ whom getting disease. Cold or heat based means being chilled or hot of triple energizer. Eexterior or interior means origin of disease of exterior or interior. Cold or heat means being chilled or hot of digestive system. Conclusions : In the clinical diagnosis using revised interpretaion, diagnosis of exterior or interior disease can be decided by symptoms of Taeyang syndrome(太陽病)'s fever and aversion to cold or not. Diagnosis of cold or heat disease can be decided by diarrhea or constipation.

• Proceedings of the KSME Conference
• /
• 2004.04a
• /
• pp.1546-1551
• /
• 2004

This paper presents a mathematical model to predict the frost properties and heal and mass transfer within the frost layer formed on a cold plate. The laminar flow equations for the air-side are analyzed. and the empirical correlations of local frost properties are employed in order to predict the frost layer growth. The correlations of local frost density and effective thermal conductivity of frost layer, obtained from various experimental conditions, are derived as functions of various frosting parameters (Reynolds number, frost surface temperature, absolute humidity and temperature of moist air, cooling plate temperature, and frost density). The numerical results are compared with experimental data and the results of various models to validate the present model, and agree well with experimental data within a maximum error of 10%. The heat and mass transfer coefficients obtained from the numerical analyses are presented, as the results, it is found that the model for frost growth using the correlation of heat transfer coefficient without solving air flow have a limitation in its application.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.10 no.1
• /
• pp.84-92
• /
• 2002

On the cold start of LPG engine, as the engine temperature has not reached its equilibrium temperature, liquid LPG could not be changed perfectly gaseous LPG, although it was passed to the vaporizer. Liquid and gas mixed fuel could influence starting ability and exhaust emission characteristics of LPG engine. In this study, the vaporization characteristic of liquid LPG was investigated with a conventional vaporizer and the vaporizer with heat source(glow plug) installed at preheated chamber inlet, by using the visualization methods and engine test. According to visualization result, even if the engine coolant temperature was $14^{\circ}C$, liquid fuel was supplied to primary chamber over 25 seconds without vaporizing from preheated chamber in such a conventional vaporizer. However, the vaporizer with heat source do not correspond with that, scarcely had been trim on glow plug when LPG began to vaporize. The effectiveness of heat source could be verified by application to the conventional LPG engine.

• Journal of Welding and Joining
• /
• v.5 no.1
• /
• pp.34-41
• /
• 1987

To explore the possible application of thermal analysis technique as a probe for finding weld defects, Hydrogen trapping phenomena in Heat Affected Zone (HAZ) of the AISI 5160 spring steel were investigated. HAZ was divided into five parts, which were used as thermal analysis specimens. Two types of trap sites were found in HAZ, ferrite/cementin interface and microvoid. The thermal analysis peak due to the ferrite/cementite interface increased its height toward the weld deposit. The thermal analysis peak due to the microvoid was the highest where the grain size was the smallest. The correspondence between the cold cracking and hydrogen trap nature is also discussed.

• Proceedings of the KIEE Conference
• /
• 1997.07d
• /
• pp.1494-1496
• /
• 1997

The MRI Magnet is a most practical application of NbTi superconductor. In this paper, we present the main research results on superconducting wires for MRI magnet which we have developed. Cu/NbTi superconducting wires were fabricated by repeat of cold working and heat-treating process after that billets were extruded. We investigated the relation of superconductivities of wires and heat treatment condition. The correlation between cross section shape of wires and work inhomogeneity of NbTi rods was investigated by microscopic observation. The more repeatation number of cold working and heat-treating process, the higher critical current is achieved.

• Proceedings of the SAREK Conference
• /
• 2009.06a
• /
• pp.990-995
• /
• 2009

Experimental basic study was performed to understand the characteristics of sub-cooled refrigerant using a cold heat storage system. This system was made up general vapor-compression refrigeration cycle added sub-cooler and ice storage tank. The purpose of this study are to application use of cold-heat storage systems multiplicity of fields and to understand of sub-cooling system. At the condition using ice storage system, the ice making process was operated during night time by electric power. And then, the refrigerant was sub-cooled using stored cold-heat after being discharged from the air cooling condenser during the day time. Comparing the result at general operation with the operation using sub-cooling system. This study showed the effects of the sub-cooled degree. The cooling performance was increased owing to the sub-cooling of refrigerant during day time, and the compressor consume power was a little decreased. Thus the COP was also increased owing to the sub-cooling of refrigerant.